An automated media exchanger is a device generally comprising a media library, a media handler, and media players. The automated media exchanger stores media, e.g., digital linear tape cartridges, in the library. When the information contained on a particular piece of media is required by a user, the media handler extracts the media from the library, transports the media to a media player, and inserts the media into the media player. The media players are devices that convert the media to a usable format, e.g., the media players may be digital linear tape players as are known in the art. The automated media exchanger may also include an imaging apparatus affixed to the media handler. The imaging apparatus is used to identify the media. Bar codes that identify the media may, as an example, be affixed to the media and the imaging apparatus may be adapted to read the bar codes to identify the media in a conventional manner.
The library typically comprises a plurality of media magazines. The magazines are generally parallelepiped structures comprising a plurality of slots or openings that are adapted to hold the media. A user may fill the magazines with media and then the user may place the magazines into the library within the automated media exchanger. There is generally some tolerance between the magazines and the structures supporting the magazines in the media library, thus, the media may be located at imprecise locations relative to the automated media exchanger. Additionally, the magazines may abut each other within the automated media exchanger, which creates additional tolerances that add to the imprecision in the location of the media. These tolerances accumulate to create a tolerance stack between the location of the media and the automated media exchanger. The location of the media with reference to the automated media exchanger, thus, becomes more imprecise as the tolerance stack increases.
The process of moving media from the library to a media player involves moving the media handler to a position adjacent to a specific piece of media in a magazine. The media handler then moves to extract the media from a specified slot in a specified magazine where the media is held. The media handler then moves adjacent to a specified media player and inserts the media into the media player. Likewise, the media handler may extract media from a media player and insert the media into a specified slot in a magazine by reversing the above-described procedure. The insertion and extraction of the media into and out of the magazines and the media player requires that the media handler precisely contact the media. If the media handler does not precisely contact the media, damage may occur to the media, the library, the media handler, and the media player.
The imprecise location of the media relative to the media handler creates problems when the automated media exchanger moves media into or out of a magazine or a media player. For example, the imprecision impedes the ability of the media handler to quickly extract and insert media into and out of a magazine and a media player without the risk of damaging the components that comprise the automated media exchanger. In order to precisely contact the media, the media handler may have to slow down to orient itself relative to the media prior to contacting the media. The media handler may, as an example, have to physically sense the location of the media in order to orient itself, which increases the operating time of the automated media exchanger.
The problem of locating the media relative to the media handler may be substantially resolved by aligning the previously described imaging apparatus, which may be affixed to the media handler, the media handler, the slots in the magazines, and other components in the automated media exchanger. An example of precisely aligning an imaging apparatus to a media handler to which it is affixed is described in U.S. patent application, Ser. No. 09/290,429 of Gardner et al. for IMAGING APPARATUS ALIGNMENT SYSTEM AND METHOD, filed on the same day as this application, which is hereby incorporated by reference for all that is disclosed therein.
Even when the imaging apparatus is aligned to the media handler, however, it is possible that the media handler itself may not be properly aligned to the other components in the automated media exchanger. This improper alignment may be due to misalignment between the image beam, which is associated with the imaging apparatus, and the aforementioned components. As previously described, proper alignment between the media handler and the magazine slots, and thus, the media, is critical in order for the media handler to successfully extract media from the magazine or to insert media into the magazine. Proper alignment between the media handler and the media players is also critical for media exchanges between the media handler and the media players.
Therefore, a need exists for an alignment system that will align the image beam associated with an imaging apparatus to the components located within an automated media exchanger.